Engine check light, no codes

[DMcGalliard]

Need help,

Just added fuel pressure gage thru the geno cap, pressure is 8psi at idle. As I was testing the gage I noticed the check light was on, looked for codes(3 on and last left at run), no codes.

The only thing I can think is that I bumped something or as I was looking for power on the switch I upset somebody. I did pull some fuses and the one marked diesel transmission was pulled when I restared the truck. I may have pulled others too, could this be the problem? The trucks runs normal and all the gages are normal and all of the fuses are back.



I did the search and I am not sure that helped, except don't take it to the dealer.



Should I just run it to see what gives? I have all my wiring fused so there should be no danger of a fire. The voltage did not come up to center of the gage and that was a concern, but I have not been watching it.



Any suggestions will be welcomed.



Dave Mc

 

[Mobius1]

Just double check all connections, maybe something was bumped...

 

[rbattelle]

I did pull some fuses and the one marked diesel transmission was pulled when I restared the truck. I may have pulled others too, could this be the problem?

That's probably the issue. It's strange that there were no codes stored, however. Normally an engine light means a code is stored in the computer.



If it's not a real problem, the light will go out after 5 consecutive restarts.



The voltage not being at the center of the gauge could be due to the action of the grid heaters (was it below 66°F?).



Ryan

 

[DMcGalliard]

Thanks for comments

I did get it to bring up a code, the code recall has to be done quickly,hold the lock down while doing it. The code is p217, coolant temp too high. I added the fan control wiring about six months ago. When I was adding the pressure switch I messed with the fan wiring, I may have opened a connection or something. The question is where is the computer getting the p217, the gage does not indicate high, I am thinking there is an open circuit back where I added the fan control was added to the main connnection.



I have tried to clear the p217 with 5 restarts and it won't clear, so there is still a problem and I need to go back and check all the wiring#@$%!.



Bring up the code does help find the problem, thanks.



Dave Mc

 

[AllianceDiesel]

Dive the truck, and when it sees enough good trips it will clear the light

 

[DMcGalliard]

Found the problem.

Oo. I located the problem in the switch for the fan control. I went back thru all the wiring I had done and it all looked good, finally took the fan control switch out of the circuit and the check light went off, put the switch back in light comes on. The computer must be look at that circuit and if it is not clean it thinks it is an open circuit or the fan is not working. The resistance across the switch was about 1 ohm. I need a switch that is clean and makes hard contact. Also if the computer is poling at the time I move the switch it will think the circuit is open, so the switching has to be instant. I have not been that happy with the way the fan control works. Wish there was some way of turning the fan on without the computer being involved. So now I am looking for the right kind of switch. I agree the code will go away after so many starts, thanks.



Thanks for the comment about the heater, I had forgot about it coming on if the temp is below 64.



That fan control circuit can be found thru the search: fan control.



Thanks, Dave Mc